Summary of Work: The MacArthur Study of Successful Aging represents a unique opportunity to assess the relationship between interleukin-6 (IL-6) and cortisol and to examine whether the IL-6-health outcome risks would be modified by cortisol over a longer follow-up period. Follow-up on the MacArthur cohort now extends through 1996 and of the original cohort, approximately one-quarter have now died. We measured IL-6 and C-reactive protein (CRP) on frozen plasma samples. We investigated the cross-sectional relationship of urinary cortisol to IL-6 and CRP and found that there was no association. Both IL-6 and CRP were related to all-cause mortality and urinary cortisol did not modify this association. The data have been used to evaluate the relationship of albumin and IL-6 and also to examine the association of IL-6 with cognitive decline. In addition, we examined the cross-sectional and longitudinal association with performance and found a relationship only with change in walking speed. We are seeking collaborative associations with other scientists to examine the relationship with uric acid and also to group the MacArthur data with other data resources to examine infections, smoking and other variables of interest. Jeremy Sussman presented this research at the 32nd Annual Meeting of the Society for Epidemiologic Research, June 10-12, 1999, Baltimore, MD. The abstract was published in AM J EPIDEMIOL S62, 149(11)1999 (Inflammation/mortality association is explained by cardiovascular risk factors. JB Sussman, TE Seeman, MS Albert LF Berkman, DG Blazer, JW Rowe, DB Reuben, and TB Harris.) This manuscript is under review at the American Journal of Epidemiology.